Module message 

Structs

AdditionalParams

Nonempty JSON object of provider-specific content metadata, serialized as an object under a named additional_params field rather than flattened. Constructors return None for empty maps. Bare deserialization rejects empty or non-object values; optional_additional_params maps null and empty objects to absence. Providers must replay only their own metadata.

Audio

Audio content containing audio data and metadata about it.

Document

Document content containing document data and metadata about it.

EmptyCallId

A provider call id was empty.

EmptyToolName

A tool name was empty.

Image

Image content containing image data and metadata about it.

Issuer

The service that issued reasoning: the descriptor name of the wire that decoded it ("anthropic"), or the model vendor where a gateway relays several ("openrouter/openai").

LocalCallId

A call id rig issued: a random (v4) UUID.

ProviderCallId

Provider-issued identifiers for replay. Single-id protocols use call_id; dual-id protocols also use item_id. Keep each identifier in its protocol slot.

Reasoning

Assistant reasoning payload with an optional provider-supplied identifier. A message carries it Sealed to the service that issued it: signatures, encrypted and redacted payloads and reasoning ids only mean something there.

Sealed

A value only its issuer may read: reasoning, whose signatures, encrypted payloads and ids mean something only to the service that produced them.

Text

Text with optional provider metadata under the named additional_params key. Unknown sibling fields are ignored on decode, not captured for replay.

ToolCall

Describes a tool call with an id and function to call, generally produced by a provider.

ToolFunction

Describes a tool function to call with a name and arguments, generally produced by a provider.

ToolName

A tool name, never empty.

ToolResult

The result of a tool call, sent back to the model.

Video

Video content containing video data and metadata about it.

Enums

AssistantContent

Assistant text, tool calls, reasoning, or images. Deserialization requires the lowercase type tag.

AudioMediaType

Describes the audio media type of the content. Not every provider supports every media type. Convertible to and from MIME type strings.

CallId

A tool call’s one identity: the id the provider issued, or one rig issued because the provider sent none.

ContentFormat

Content representation as base64, text, or a URL.

DocumentMediaType

Describes the document media type of the content. Not every provider supports every media type. Includes also programming languages as document types for providers who support code running. Convertible to and from MIME type strings.

DocumentSourceKind

The kind of image source (to be used).

ImageDetail

Describes the detail of the image content, which can be low, high, or auto (open-ai specific).

ImageMediaType

Describes the image media type of the content. Not every provider supports every media type. Convertible to and from MIME type strings.

MediaType

Helper enum that tracks the media type of the content.

Message

A provider-agnostic chat message.

MessageError

Error type to represent issues with converting messages to and from specific provider messages.

ReasoningContent

A typed reasoning block used by providers that emit structured thinking data.

ToolChoice

ToolResultContent

Describes one typed item in a tool result.

UserContent

User text, tool results, or media. Supported source kinds and media types depend on the target provider.

VideoMediaType

Describes the video media type of the content. Not every provider supports every media type. Convertible to and from MIME type strings.

Constants

EMPTY_RESPONSE_ERROR

Shared error text for an invalid empty response choice. Provider decoders must exempt legal empty outcomes, including recognized output truncation, before calling require_non_empty_response.

Traits

MimeType

Trait for converting between MIME types and media types.

Functions

canonical_streamed_choice

Groups streamed choices as reasoning, text, tool calls, then images, preserving order within each group. Choices without reasoning or tool calls retain their original order.

keys_lost_in_round_trip

Returns dot-separated paths whose original values are missing or changed after a round trip. Ignores added keys, null object members, and missing object members whose original value was an empty object. Array positions are compared individually.

non_empty

Returns None for an empty list or Some(items) otherwise. Individual items are not inspected.

optional_additional_params

Deserializes optional metadata, mapping null and empty objects to None. Nonempty objects produce metadata; other shapes return a deserialization error.

ordered_assistant_content

Concatenates reasoning, text, and trailing content in that order without dropping items. Each group’s input order is preserved.

require_non_empty

Returns items unchanged unless the list is empty, then calls error once. Does not inspect individual items: empty text can carry replay signatures. Request conversions that discard content must validate the converted list when their wire requires at least one block.

require_non_empty_response

Returns a response error using EMPTY_RESPONSE_ERROR for an empty list. Callers must handle provider-legal empty outcomes before invoking this guard.

turn_delivered_no_answer

Returns whether the choice contains no nonempty text, tool call, or image. Reasoning alone is not an answer, even when retained in history.